E. W. BERGER ON THE CUBOMEDUS. 55 
quite evident how Schewiakoff should have interpreted the parts of 
the long pigment cells in the vitreous body as conical pigmented caps 
placed opposite his supporting cells (long pigment cells). 
Finally, since Schewiakoff had only twelve marginal bodies to 
study, and since this tissue is difficult to preserve properly, I do not 
believe that I am doing Schewiakoff any injustice by explaining away 
his results as I have done. This fact remains, that Conant and 
myself agree in all points in which we differ from Schewiakoff. 
To Conant belongs the credit of having first demonstrated the 
prismatic structure of the vitreous body, and he also regarded the 
prisms as a part of the retinal cells. H. V. Wilson’:* suggested, 
however, some years prior to Conant, that the vitreous body might 
be of a prismatic structure. Conant had evidence also of both the 
prism and pyramid fibers, as is well shown in his figures of trans- 
verse sections but he found his evidence too meager to make any 
very definite statements. Indeed, Conant concludes that there are 
three kinds of fibers in the vitreous body and complains of finding 
but two kinds of cells in the so-called retina (pigmented and nuclear 
zones) to which to refer them. He saw the pyramids with their 
axial fibers as lighter areas in transverse sections of the vitreous 
body (his Figs. 64 and 68, and my Figs. 1, 4 and 7), but suggests 
that they may be the same as the long pigment cells, the cells 
having only to project themselves or their pigment in order to 
become long pigment cells. This suggested to him to preserve 
material both in the light and in the dark. I do not think Conant’s 
supposition to be a fact, for I find the pyramids in specimens 
preserved in the light as well as in the dark. It is, of course, 
possible that the pyramid cells are in a stage of structural transition 
to the long pigment cells, for, besides their pigmentation, they also 
have like nuclei. Furthermore, I held for a long time with Conant 
that there may be only two kinds of cells in the retina, but I soon 
found the pyramids so definitely shown as to leave no doubt but 
that they represented a third kind of cell. For me it remained to 
first definitely see all the fibers in the vitreous body as also the 
pyramids in sagittal sections. 
Conant describes the long pigment cells with their fibers extending 
between the prisms of the vitreous body quite as I have described, 
and in this my work is only confirmatory of his. Conant does not, 
however, describe the several centrad processes of these cells, nor is 
